Health Library

Health Library Explorer
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z A-Z Listings

What Is Thyroid Cancer?

Cancer happens when cells in the body change and grow out of control. These cells can form lumps of tissue called tumors. Cancer that starts in cells of the thyroid is called thyroid cancer. It's also called thyroid carcinoma.

Understanding the thyroid

The thyroid is a small, butterfly-shaped gland in front of the neck, just below the Adam's apple. The thyroid controls the rate at which every part of the body works. This is called metabolism . The thyroid gland regulates the metabolism by making thyroid hormone, a chemical that carries messages from the thyroid to the rest of the body through the bloodstream. The thyroid also makes the hormone called calcitonin. This regulates how calcium is used in the body. 

Front view of head and neck showing trachea and thyroid gland.

When thyroid cancer forms

Cells in the thyroid may grow out of control, forming small lumps called nodules. But most thyroid nodules aren't cancer. The thyroid may also enlarge (swell). Thyroid cancer can spread from the thyroid to other parts of the body. This spread is called metastasis. In general, the more cancer spreads, the harder it is to treat.

There are 5 main types of thyroid cancer:

  • Papillary thyroid cancer, which is the most common type

  • Follicular thyroid cancer

  • Hurthle cell cancer

  • Medullary thyroid cancer

  • Anaplastic thyroid cancer 

Treatment choices for thyroid cancer

You and your healthcare provider will discuss a treatment plan that's based on your type of cancer and your personal needs. Treatment choices may include:

  • Surgery. This removes part or all of the thyroid gland.

  • Radioiodine therapy. This uses radioactive iodine to destroy thyroid cancer cells in the body.

  • External radiation therapy. This uses rays of energy directed right at the tumor to kill cancer cells.

  • Hormone therapy. This blocks or removes the hormones that help the cancer grow.

  • Chemotherapy. This uses strong medicines to kill cancer cells all over the body.

  • Targeted therapy. This targets the cancer cells' genes or proteins that allow cancer growth and survival.

  • Watchful waiting with frequent healthcare checkups. This is done to look for any problems or symptoms that have occurred since your last appointment.

Write down any questions you have about thyroid cancer, and bring them with you when you talk with your provider. They can help you understand more about this cancer.

Online Medical Reviewer: L Renee Watson MSN RN
Online Medical Reviewer: Marianne Fraser MSN RN
Online Medical Reviewer: Robert Hurd MD
Date Last Reviewed: 10/1/2021
© 2000-2023 The StayWell Company, LLC. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.